The Clip Lines command has the ability to break a selected set of lines at the location where they cross a boundary or other selected line without deleting any data - you can also delete the lines Inside or outside a boundary at the same time if you want to.

The Clip Lines command has the ability to break a selected set of lines at the location where they cross a boundary or other selected line without deleting any data - you can also delete the lines Inside or outside a boundary at the same time if you want to.